Accompanying a multifunction and high performance of a semiconductor integrated circuit in these years, a high density packaging of an IC package mounting an IC chip (hereinafter referred to as semiconductor device or simply semiconductor) is requested. As a result, a BGA (Ball Grid Array) which is comparatively compact and is a spherical connection end terminal possible to be made multi-pin becomes to be used instead of a conventionally used QFP (Quad Flatpack Package) and the like.
This is thanks to a fact that an adoption of the spherical connection end terminal allows a reduction of an attachment area and a placement space of the IC package, and a thickness reduction of the IC package itself.
The trend of the miniaturization is in these years rapidly progressing and the spherical connection end terminal itself tends to be more miniaturized. In fact a pitch of the spherical connection end terminal becomes from 0.5 to 0.3 mm, thereby a further narrow pitch being proceeding.
Under these circumstances a terminal electrically connecting with the spherical connection end terminal is also requested to handle the miniaturization and high integration.
In advance, the applicant of the present invention disclosed in Japanese patent application 2001-077338 (applied in Mar. 19, 2001) a spiral contactor in which a terminal contacting a spherical connection end terminal has a spiral shape, and a width of the terminal becomes narrower as the terminal proceeds from a base end side to a top side.
FIG. 11A is a plan view in which a part of a spiral contactor 30 disclosed in the application is represented partially enlarged; FIG. 11B is a section drawing of a line F—F shown in FIG. 11A.
As shown in FIG. 11A, the spiral contactor 30 is constituted of a plurality of spiral-shaped terminals 31 (hereinafter referred to as spiral-shaped terminals) disposed like a lattice on a board (hereinafter referred to as insulation board) composed of insulation materials.
Each spiral-shaped terminal 31 has a circular shape and is arranged in a separated state from adjacent spiral-shaped terminals 31 at a predetermined distance in longitudinal and lateral directions.
A disposition of each spiral-shaped terminal 31 of the spiral contactor 30 is set so that when the spiral contactor 30 is used as a contactor to perform an electrical connection with an electronic component, it can one for one overlap a spherical connection end terminal disposed at a semiconductor device like a lattice.
In the spiral contactor 30 shown in the drawings, considering a diameter of the spherical connection end terminal disposed at the semiconductor device, distances p1 from a center of a spiral-shaped terminal 31 till those of adjacent spiral-shaped terminals 31 are set.
In the spiral-shaped terminal 31 is formed a spiral (volute) form probe 32, and at its center portion is ensured an approximately circular space with a diameter h.
A length of the probe 32 is set so that a contact length of the probe 32 and spherical connection end terminal becomes not less than one rotation (accurately one and one fourth rotations) when contacting the spherical connection end terminal.
That is, the length of the probe 32 is set to be a length which can keep an electrical connection surely contacting the spherical connection end terminal when the probe 32 and spherical connection end terminal are contacted.
In addition, as shown in FIG. 11A, a width size in each point a to f of the probe 32 is designed to be a shape in which a relationship of a>b>c>d>e>f is realized. That is, the width of the probe 32 is set to become narrower as the probe 32 nears its top.
However, in the spiral terminal 30 equipped with the spiral-shaped end terminal 31, the width of the probe 32 becomes broader as the probe 32 nears from its top E to base end R, so if the spiral contactor 30 is constituted by the spiral-shaped terminals 31 being arranged at a narrow pitch in order to handle the miniaturization of the spherical connection end terminal of the semiconductor device, a wound number of the probe 32 (contact length of the probe 32 and spherical connection end terminal) cannot be made more, thereby the wound number of the probe 32 resulting in being decreased.
FIG. 12A is a partially enlarged plan view of a spiral contactor 40 in which a disposition distance of spiral-shaped terminals 41 is set at a narrower pitch; FIG. 12B is a section drawing of a line G—G shown in FIG. 12A.
That is, as shown in FIG. 12A, because in the spiral contactor 40 a width W of the probe 42 becomes narrower as the probe 42 proceeds from its base end R to top E, a contact length of the probe 42 and spherical connection end terminal becomes not more than one rotation (accurately three fourths rotation), thereby there existing a problem that a sufficient contact with the spherical connection end terminal is not ensured.
In addition, when a thorough hole (concave portion) making it possible to be pushed in by the spherical connection end terminal is not provided on an insulation board to make it ultra-thin, there exists a program that a spiral contactor cannot be adopted as the insulation board.
Under these circumstances, there exists a request for a contactor which can use even a semiconductor device and microminiature pair chip in which a disposition distance of the spherical connection end terminal is narrower pitched, and which can sufficiently ensure a contact length (at least a contact length not less than one rotation) with the spherical connection end terminal.
Moreover, there also exists a request for a contactor which can adopt even an insulation board in which a thorough hole is not provided.